Refrigerator

ABSTRACT

In a refrigerator, a cooling air duct for supplying cooling air to an ice making chamber is installed to be exposed from an inner wall face of a refrigerator chamber. Thus, the thickness of the refrigerator main body can be sufficiently secured, and accordingly, temperature of cooling air flowing through the cooling air duct can be prevented from being increased by external air. Also, since the cooling air duct is installed in a receiving space, a generation of frost in the vicinity of the cooling air duct can be prevented, and an increase in a fabrication cost and power consumption when an anti-frost heater is installed can be prevented.

The present application claims priority to Korean Application No. 10-2010-0073044 filed in Korea on Jul. 28, 2010, the entire contents of which is hereby incorporated by reference in its entirety.

1. FIELD OF THE INVENTION

The present invention relates to a refrigerator and, more particularly, to a refrigerator in which a cold air duct, which faces an ice making chamber in a freezing chamber, is detachably installed.

2. DESCRIPTION OF THE RELATED ART

In general, a home refrigerator is a device having a certain receiving space to maintain food items, or the like, at a low temperature. The receiving space of the home refrigerator is divided into a refrigerating chamber maintained above zero and a freezing chamber maintained below zero according to a low temperature range. Recently, a refrigerator including an automatic ice making apparatus is increasing as demand for ice is on the rise.

The automatic ice making apparatus (referred to as an Ice making apparatus', hereinafter) may be installed in the freezing chamber according to am aspect of a refrigerator or installed in the refrigerating chamber according to circumstances. When an ice making chamber including the ice making apparatus is installed in the refrigerating chamber, the cooling air duct for guiding cooling air from a freezing chamber to an ice making chamber is provided to guide cold air of the freezing chamber to the ice making chamber.

For example, in a 3-door bottom freezer type refrigerator in which a freezing chamber is disposed at a lower portion and a refrigerating chamber is installed at an upper portion, an evaporator is installed on a rear wall face of the freezing chamber and an ice making chamber is installed at an upper portion of the refrigerating chamber door. A cooling air duct guiding cooling air of the freezing chamber to the ice making chamber is installed at an inner side of one wall face of the refrigerating chamber, i.e., between an outer case and an inner case. A pair of cooling air ducts are provided, and one is used as a supply duct and the other is used as a recovery duct. Thus, a portion of cooling air generated in the freezing chamber is guided to the ice making chamber along the supply side cooling air duct to cool the interior of the ice making chamber, and after the cooling operation is finished in the ice making chamber, cooling air is recovered along the recovery side cooling air duct. This process is repeatedly performed.

However, in the related art refrigerator, since the cooling air duct is installed on the side wall face f the refrigerating chamber, when cooling air which passes through the cooling air duct is heat-exchanged with external air, cooling air is lost. Namely, a foaming agent is filled between the inner case and the outer case forming the wall face of the refrigerator prevents heat transmission between the interior of the refrigerator and external air. However, when the cooling air duct is installed between the inner case and the outer case, the thickness of the foaming agent is reduced as much as the space in which the cooling air duct is installed, narrowing the space between the cooling air duct and external air to cause a loss of cooling air.

In addition, when the cooling air duct is installed on the side wall face of the refrigerator, a heater must be operated in order to prevent frost, increasing the loss of cooling air as much and power consumption. Namely, when the cooling air duct is buried at the inner side of the side wall face of the refrigerator, as described above, the space between the outer case of the refrigerator and the cooling air duct is reduced, having possibility in which an outer circumferential surface of the cooling air duct is frosted. In consideration of this, a heater is installed between the cooling air duct and the outer case of the refrigerating chamber to prevent a generation of frost or defrost when frost is generated. In this case, however, the temperature of cooling air which passes through the cooling air duct may be increased by heat generated by the heater to increase the loss of cooling air. Also, since the heater is required to be frequently operated, power consumption is increased as much.

SUMMARY OF THE INVENTION

An aspect of the present invention provides a refrigerator capable of securing a sufficient insulation thickness between cooling air, which passes through a cooling air duct, and external air, thus reducing a loss of cooling air.

Another aspect of the present invention provides a refrigerator capable of preventing an outer circumferential surface of a cooling air duct from being frosted, thus reducing or excluding the use of a heater for anti-frost with respect to the cooling air duct, reducing power consumption, and preventing temperature of cooling air which passes through the cooling air duct from increasing by a heater.

According to an aspect of the present invention, there is provided a refrigerator including: a refrigerator main body having a receiving space; and a refrigerator door coupled to the refrigerator main body to open and close the receiving space of the refrigerator main body, wherein the refrigerator main body further includes a cooling chamber for generating cooling air, the refrigerator door further includes an ice making chamber for making ice by using cooling air generated in the cooling chamber, and a cooling air duct guiding cooling air from the cooling chamber to the ice making chamber installed on an inner wall face of the refrigerator main body forms the receiving space.

According to another aspect of the present invention, there is provided a refrigerator including: a refrigerator main body in which a receiving space and a cooling chamber are demarcated; a refrigerator door coupled to the refrigerator main body to open and close the receiving space of the refrigerator main body and having an ice making chamber; an evaporator installed in the cooling chamber of the refrigerator main body; an ice making unit provided in the ice making chamber of the refrigerator door; and a cooling air duct provided in the refrigerator main body and guiding cooling air generated in the cooling chamber to the ice making chamber, wherein the cooling air duct is detachably installed on an inner wall face of the refrigerator main body.

According to another aspect of the present invention, there is provided a refrigerator, in which a receiving space for receiving food items and a cooling chamber for generating cooling air are demarcated and the receiving space and the cooling chamber are disposed to be demarcated from an ice making chamber, wherein the cooling chamber and the ice making chamber are connected by a cooling air duct which passes through the receiving space, and the cooling air duct is installed on an inner wall face of the receiving space.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a 3-door bottom-freezer type refrigerator according to an embodiment of the present invention;

FIG. 2 is an exploded perspective view of a cooling air duct in the refrigerator in FIG. 1;

FIG. 3 is a vertical sectional view sowing an assembled cooling air duct in FIG. 2;

FIG. 4 is a sectional view taken along line I-I in FIG. 3;

FIG. 5 is a perspective view showing other example of the cooling air duct in FIG. 2; and

FIGS. 6 and 7 are vertical sectional views showing other examples of the cooling air duct in the refrigerator according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A refrigerator according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a perspective view of a 3-door bottom-freezer type refrigerator according to an embodiment of the present invention.

As shown in FIG. 1, in the refrigerator according to an embodiment of the present invention, a freezing chamber 2 is formed at a lower portion of a refrigerator main body 1 in order to freeze and keep food items in storage, and one refrigerating chamber 3 is formed at an upper portion of the refrigerator main body 1 in order to refrigerate and keep food items in storage.

The refrigerator main body 1 includes an outer case 11 forming an external appearance and an inner case 12 disposed at an inner side of the outer case 11, separated from the outer case 11 with a foaming agent (not shown) charging space therebetween, and forming a food item receiving space therein. The inner case 12 is divided into a freezing chamber 2 and a refrigerating chamber 3 by a horizontal barrier 13 formed therebetween.

One freezing chamber door 4 is installed at the freezing chamber 2 in order to open and close the freezing chamber 2 in a sliding manner, and a plurality of refrigerating chamber doors 5 are installed at both sides of the refrigerating chamber 3 in order to open and close the refrigerating chamber 3 in a rotating manner from both sides.

A mechanic chamber including a compressor and a condenser is formed at a lower end of a rear face of the refrigerator main body 1, and an evaporator 6 (See FIG. 2) is installed on a rear wall face, side wall face, or an upper wall face of the freezing chamber 2 or in the interior of the barrier 13 demarcating the freezing chamber 2 and the refrigerating chamber 3. The evaporator is connected with the condenser and the compressor to supply cooling air to the refrigerating chamber or the freezing chamber 2. One evaporator may be installed to distributedly supply cooling air to the freezing chamber 2 and the refrigerating chamber 3, or a freezing chamber evaporator and a refrigerating chamber evaporator may be provided to independently supply cooling air to the freezing chamber 2 and the refrigerating chamber 3. Here, for example, the evaporator is installed in the freezing chamber.

An ice making chamber 51 for making ice and keeping ice in storage is formed at an upper inner wall face of one refrigerating chamber door 5, and an ice making device 7 for making ice is installed in the interior of the ice making chamber 51. An ice storage container 8 is installed at a lower side of the ice making device 7 and receives ice made in the ice making device 7 to keep it in storage. A dispenser (not shown) is installed at a lower side of the ice making chamber 51 to be exposed from a front side of the refrigerating chamber door 5 such that ice stored in the ice storage container 8 can be drawn out from the exterior of the refrigerator.

In this manner, in the refrigerator, when a load in the freezing chamber 2 or the refrigerating chamber 3 is detected, the compressor is operated to allow cooling air to be generated from the evaporator 6. A portion of the cooling air cools the freezing chamber 2 and then is supplied to the refrigerating chamber 3 through a refrigerating chamber supply duct (not shown), and another portion of the cooling air generated in the evaporator 6 is supplied to the ice making chamber 51. The cooling air supplied to the ice making chamber 51 is heat-exchanged to allow the ice making device 7 mounted in the ice making chamber 51 to make ice and then recovered to the freezing chamber 2 or supplied to the refrigerating chamber. Ice made in the ice making device 7 is stored in the ice storage container 8 and the drawn out to the exterior according to a request from the dispenser. This process is repeatedly performed.

Here, when the evaporator 6 is installed in the freezing chamber 2, a loss of cooling air is required to be reduced when cooling air generated in the evaporator 6 is guided to the ice making chamber 51 disposed at an upper side of the refrigerating chamber door 5, and power consumption of the refrigerator may be reduced when supplying cooling air, supplied to the ice making chamber 51, to the refrigerating chamber 3 as necessary. In the present embodiment, a loss of cooling air when cooling air is transferred from the to freezing chamber to the ice making chamber is reduced and cooling air of the ice making chamber is supplied to the refrigerating chamber, thus reducing power consumption of the refrigerator.

FIG. 2 is an exploded perspective view of a cooling air duct in the refrigerator in FIG. 1. FIG. 3 is a vertical sectional view sowing an assembled cooling air duct in FIG. 2. FIG. 4 is a sectional view taken along line I-I in FIG. 3.

As illustrated, in the refrigerator main body according to the present embodiment, a plurality of cooing air passages 131 and 132 are formed in a penetrative manner in the barrier 13 demarcating the freezing chamber 2 and the refrigerating chamber 3, and a freezing chamber cooling air duct (referred to as a ‘freezing chamber duct’, hereinafter) 20 and a refrigerating chamber cooling air duct (referred to as a ‘refrigerating chamber duct’, hereinafter) 30 are formed to communicate with both ends of the cooling air passages 131 and 132.

Both the freezing chamber duct 20 and the refrigerating chamber duct 30 may be detachably coupled to an inner wall face of the refrigerator main body 1, namely, on the inner wall face of the inner case 12, or any one of the freezing chamber duct 20 and the refrigerating chamber duct 30 may be detachably coupled to the inner wall face, and the other may be buried between the outer case and the inner case as those in the related art refrigerator. The freezing chamber duct 20 and the refrigerating chamber duct 30 may be fastened to the inner wall face of the refrigerator main body 1 through screws or may be detachably coupled to the inner wall face by using a protrusion and a recess. Here, a sealing material (not shown), such as a gasket, may be installed between the freezing chamber duct 20 and the refrigerating chamber duct 30 and the inner wall face.

The freezing chamber duct 20 may be formed extendedly and have a hexahedral shape. A rear side, of the freezing chamber duct 20, in contact with a rear wall face of the freezing chamber 2 is open to form one opening end, and an upper side, of the freezing chamber duct 20, in contact with a lower surface of the barrier 13 is open to form the other opening end.

One opening end of the freezing chamber duct 20 is coupled to communicate with the cooling chamber accommodating the evaporator, and the other opening end of the freezing chamber duct 20 is coupled to communicate with a lower opening end of one cooling air passage (referred to as a ‘first cooling air passage’, hereinafter) 131 of the barrier 13.

Here, a lower opening end of another cooling air passage (referred to as a ‘second cooling air passage’, hereinafter) 132 of the barrier 13 may be formed to communicate with the freezing chamber 2. However, a recovery side freezing camber duct (not shown) may be coupled to communicate with the lower opening end of the second cooling air passage 132. In this case, the recovery side freezing chamber duct may be coupled to communicate with the recovery side of the cooling chamber.

The freezing chamber duct 20 includes only a supply side freezing chamber duct, while the refrigerating chamber duct 30 may include both the supply size refrigerating chamber duct 31 and the recovery side refrigerating chamber duct 32. As the supply size refrigerating chamber duct 31 and the recovery side refrigerating chamber duct 32, a plurality of flow paths constituting a supply side and a recovery side may be recessed on one plate.

A lower opening end 311 of the supply side refrigerating chamber duct 31 communicates with an upper opening end (not shown) of the first cooling air passage 131 of the barrier 13, and a lower opening end 321 of the recovery side refrigerating chamber duct 32 communicates with an upper opening end (not shown) of the second cooling air passage 132 of the barrier 13.

The upper opening end (referred to as a ‘supply side upper opening end’, hereinafter) 312 of the supply side refrigerating chamber duct 31 communicates with an ice making chamber entrance 511 (to be described), and the upper opening end (referred to as a ‘recovery side upper opening end’, hereinafter) of the recovery side refrigerating chamber duct 32 communicates with an ice making chamber exist 512 (to be described).

The supply side upper opening end 312 and the recovery side upper opening end 322 of the refrigerating chamber duct 30 are formed in a penetrative manner toward the front side of the refrigerator main body 1, i.e., the refrigerating chamber door 5, as shown in FIGS. 3 and 4.

The ice making chamber 51 is formed by a sealing projection 510 protruded in a band shape on an inner side of the refrigerating chamber door. Namely, the ice making chamber 51 is defined as an inner space formed by the sealing projection 510. Thus, the ice making chamber entrance 511 is formed in a penetrative manner on one portion of the sealing projection 510 toward the ice making chamber 51, and the ice making chamber exit 512 is formed in a penetrative manner on another portion of the sealing projection 510 toward the refrigerating chamber duct 32 from the ice making chamber 51. For the sake of convenience, the ice making chamber entrance 511 and the ice making exit 512 are illustrated to be formed on one face of the sealing projection 510.

When the supply side upper opening end 312 and the recovery side upper opening end 322 of the refrigerating chamber duct 30 are formed at the front side, a duct receiving portion (not shown) may be formed to be recessed with a certain depth on a corresponding face 513 of the sealing projection 510 corresponding to the upper opening ends 312 and 322 such that the end of the refrigerating chamber duct 30 can be inserted thereinto, or the corresponding face 513 may be formed to be flat as shown in FIGS. 1 to 3.

As shown in FIG. 5, the supply side upper opening end 312 and the recovery side upper opening end 322 of the refrigerating chamber duct 30 may be formed to penetrate in a widthwise direction of the supply side refrigerating chamber duct 31 and the recovery side refrigerating chamber duct 32, respectively. In this case, duct receiving portions 515 and 516 may be formed with a certain depth on the sealing face 514 forming an outer side of the sealing projection 510 to allow the supply side refrigerating chamber duct 31 and the recovery side refrigerating chamber duct 32 to be inserted therein, and the ice making chamber entrance 511 and the ice making chamber exit 512 may be formed at the side of the duct receiving portions 515 and 516.

The refrigerator according to an embodiment of the present invention as described above has the following operational effects.

Namely, when ice making is requested in a state in which the refrigerating chamber door 5 is closed, the ice making device of the ice making chamber 51 is turned on and ice making operation starts. When the ice making operation starts, a water supply unit (not shown) supplies water to an ice making container (not shown) of the ice making device 7.

Next, when water supply is completed, water in the ice making container is exposed to cooling air supplied to the ice making chamber for more than a certain time and thus frozen. Namely, when the refrigerating chamber door 5 is closed, a damper (not shown) is open by the refrigerating chamber door 5 and cooling air generated by the evaporator 6 is introduced into the freezing chamber duct 20, and the cooling air is introduced into the refrigerating chamber duct 31 through the first cooling air passage 131. The cooling air is introduced into the ice making chamber 51 to freeze water of the ice making container.

Thereafter, cooling air heat-exchanged with the water in the ice making chamber 51 is returned to the freezing chamber 2 through the recovery side refrigerating chamber duct 32 and the second cooling air passage 132 of the refrigerator main body 1 and mixed with cooling air supplied to the freezing chamber 2 so as to be recovered.

In this manner, since the cooling air duct is installed to be exposed from the inner wall face of the refrigerator main body, the thickness of the refrigerator main body can be sufficiently secured, and thus, the temperature of cooling air flowing through the cooling air duct can be prevented from being increased by external air.

Also, since the cooling air duct is installed in the refrigerator, a generation of frost in the vicinity of the cooling air duct can be prevented, and thus, an increase in a fabrication cost and power consumption when an anti-frost heater is installed can be prevented.

Meanwhile, a refrigerator according to another embodiment of the present invention will now be described.

In the foregoing embodiment, the freezing chamber duct and the refrigerating chamber duct are installed at the inner wall face of the refrigerator main body, but in the present embodiment, as shown in FIG. 6, the freezing chamber duct 20, the refrigerating chamber duct 30, in particular, the refrigerating chamber duct 30, are installed on a the rear wall face of the refrigerator main body 1. In this case, the refrigerating chamber duct 30 is connected to the rear wall face and upper side wall face of the refrigerator main body 1 to form the supply side upper opening end 312 and the recovery side upper opening end 322 of the refrigerating chamber duct 30.

In this case, the operational effect is similar to that of the foregoing embodiment, so a detailed description thereof will be omitted. Here, a cooling air discharge hole 315 communicating with the refrigerating chamber is formed in the middle of the refrigerating chamber duct 30, so that cooling air can be supplied to the refrigerating chamber 3 through the cooling air discharge hole 315. Accordingly, there is no need to additionally install a refrigerating chamber cooling air duct to supply cooling air to the refrigerating chamber 3, and thus, a fabrication cost can be reduced and the capacity of the refrigerating chamber can be increased.

Meanwhile, as shown in FIG. 7, the cooling air duct may be further formed on the refrigerating chamber door 5. In this case, a supply side door cooling air duct (referred to as a ‘supply side door duct’, hereinafter) 52 and a recovery side door duct (referred to as a ‘recovery side door duct’, hereinafter) 53 may be formed at an inner side of the sealing projection 510 of the refrigerating chamber door 5, namely, at the inner side of the sealing projection 510 forming the ice making chamber 51 of the refrigerating chamber door 5 such that they communicate with the supply side upper opening end 312 and the recovery side upper opening end 322 of the refrigerating chamber duct 30. Reference numerals 521 and 522 denote lower and upper opening ends of the supply side door duct, respectively, and 531 and 532 denote lower and upper opening ends of the recovery side door duct, respectively.

In this case, the operational effect is similar to that of the foregoing embodiment, a detailed description thereof will be omitted. In this case, since the length of the refrigerating chamber duct protruded to the inner side of the refrigerating chamber is short, a reduction in the capacity of the refrigerating chamber due to the refrigerating chamber duct can be prevented.

As the present invention may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims. 

1. A refrigerator comprising: a refrigerator main body having a receiving space; and a refrigerator door coupled to the refrigerator main body to open and close the receiving space of the refrigerator main body, wherein the refrigerator main body further includes a cooling chamber for generating cooling air, the refrigerator door further includes an ice making chamber for making ice by using cooling air generated in the cooling chamber, and a cooling air duct guiding cooling air from the cooling chamber to the ice making chamber installed on an inner wall face of the refrigerator main body forms the receiving space.
 2. The refrigerator of claim 1, wherein the cooling air duct is detachably attached to an inner wall face of the refrigerator door or the refrigerator main body.
 3. The refrigerator of claim 1, wherein a supply side flow path and a recovery side flow path of the cooling air duct are separately formed.
 4. The refrigerator of claim 3, wherein the supply side flow path and the recovery side flow path of the cooling air duct are integrally formed on a single plate.
 5. The refrigerator of claim 3, wherein a sealing projection is formed on an inner side of the refrigerator door and protruded so as to be inserted into the receiving space of the refrigerator main body to form the ice making chamber, and an ice making chamber entrance and an ice making chamber exit are formed to allow the ice making chamber and the cooling air duct to communicate with each other.
 6. The refrigerator of claim 5, wherein an opening of the cooling air duct is formed on a section of the cooling air duct in a lengthwise direction of the cooling air duct, and the ice making chamber entrance and the ice making chamber exit are formed on a face facing a rear side when the refrigerator door is closed.
 7. The refrigerator of claim 5, wherein the opening of the cooling air duct is formed on a face perpendicular to a lengthwise direction of the cooling air duct, and the ice making chamber entrance and the ice making chamber exit are formed on a face corresponding to the inner wall face of the refrigerator main body when the refrigerator door is closed.
 8. The refrigerator of claim 5, wherein a duct receiving portion is formed to be recessed in the vicinity of the ice making chamber entrance and the ice making chamber exit, and the cooling air duct is inserted into the duct receiving portion.
 9. The refrigerator of claim 3, wherein the refrigerator door further includes a supply side cooling air duct and a recovery side cooling air duct, and the supply side cooling air duct and the recovery side cooling air duct independently communicate with the supply side cooing air duct and the recovery side cooling air duct provided at the receiving space of the refrigerator main body.
 10. The refrigerator of claim 1, wherein the cooling air duct is formed on a side wall face constituting the receiving space of the refrigerator main body.
 11. The refrigerator of claim 1, wherein the cooling air duct is formed on an upper wall face constituting the receiving space of the refrigerator main body.
 12. The refrigerator of claim 1, wherein the refrigerator main body is includes a freezing chamber and a refrigerating chamber demarcated by a barrier, an evaporator is installed at the freezing chamber side, a cooling air passage is formed in a penetrative manner on the barrier, and a freezing chamber side cooling air duct and a refrigerating chamber side cooling air duct are installed in the freezing chamber and the refrigerating chamber, respectively, such that they communicate with both ends of the cooling air passage.
 13. The refrigerator of claim 1, wherein the refrigerator main body includes a freezing chamber and a refrigerating chamber demarcated by a barrier, an evaporator is installed in the interior of the barrier, a cooling air passage is formed to be open at one side of the barrier, and the cooling air duct is installed in the refrigerating chamber such that it communicates with the opening end of the cooling air passage.
 14. The refrigerator of claim 1, wherein the refrigerator main body includes a freezing chamber and a refrigerating chamber demarcated by a barrier, an evaporator is installed at the refrigerating chamber side, and the cooling air duct is installed in the refrigerating chamber.
 15. The refrigerator of claim 1, wherein the cooling air duct includes a cooling air discharge hole communicating with the receiving space of the refrigerator main body.
 16. A refrigerator comprising: a refrigerator main body in which a receiving space and a cooling chamber are demarcated; a refrigerator door coupled to the refrigerator main body to open and close the receiving space of the refrigerator main body and having an ice making chamber; an evaporator installed in the cooling chamber of the refrigerator main body; an ice making unit provided in the ice making chamber of the refrigerator door; and a cooling air duct provided in the refrigerator main body and guiding cooling air generated in the cooling chamber to the ice making chamber, wherein the cooling air duct is detachably installed on an inner wall face of the refrigerator main body.
 17. The refrigerator of claim 16, wherein the cooling air duct includes a supply side flow path and a recovery side flow path, and the supply side flow path and the recovery side flow path are integrally formed by using a single plate.
 18. The refrigerator of claim 16, wherein a sealing projection forming the ice making chamber is protrusively formed on the refrigerator door such that it is inserted into the receiving space, and the sealing projection includes an ice making chamber entrance and an ice making chamber exit allowing the cooling air duct and the ice making chamber to communicate with each other.
 19. A refrigerator, in which a receiving space for receiving food items and a cooling chamber for generating cooling air are demarcated and the receiving space and the cooling chamber are disposed to be demarcated from an ice making chamber, wherein the cooling chamber and the ice making chamber are connected by a cooling air duct which passes through the receiving space, and the cooling air duct is installed on an inner wall face of the receiving space.
 20. The refrigerator of claim 19, wherein the cooling air duct is detachably coupled to the inner wall face of the receiving space. 